Self-balancing spindle construction



April 2, 1957 L. w. JENKINS 2,787,114

SELF-BALANCING SPINDLE CONSTRUCTION 7 Filed March 18, 1954 5 Sheets-Sheet l i l i a f I ,0

INVENTOR LOUIS W. JENKINS,

ATTORNEYS April 2, 1957 L. w. JENKINS 2,787,114

SELF-BALANCING SPJINDLE CONSTRUCTION I Filed March 18, 1954 3 Sheets-Sheet 2 FIG. 2

INVENTOR LQUEQ JENKINS ATTORNEY5 April 2, 1957 L. w. JENKINS 2,787,114

SELF-BALANCING SPINDLE CONSTRUCTION Filed March 18, 1954 3 Sheets-Sheet 3 INVENTOR LOUIS W. JENKINS ATTORNEYS United States Patent O SELF-BALANCING SPINDLE CONSTRUCTION Louis W. Jenkins, Concord, N. c.

Application March 18, 1954, Serial No. 417,059

5 Claims. c1.s7- 130 The invention relates to a unitary spindle construction mounted in mechanical floated relation upon a base therefor, said spindle construction comprising a whirl sleeve mounted in bearings on said base and a vertical spindle attached at one end by a flexible connection to the base so as to be freely tiltable in a plane perpendicular to the axis of rotation, the flexible connection including universal connecting means at the center of gravity of the base to produce a self-balancing and self-centering of the spindle base and connection which eliminates the vibrations and stresses due to the rocking of the bolster in the high speed operations which are demanded in the use of modern textile machinery.

Very high speeds are demanded in modern textile operations, but the spindle constructions used in the prior art develop heavy stress forces during high speed operation and particularly at the upper speed limit to produce imperfectly balanced packages. This results in excessive vibration, noise, strain, wear, and rocking of the bolster.

Geometric self-centering has been previously attempted but it did not solve the problem because the unbalanced loads tend to swing centrifugally away from the geometric axis of symmetry.

Other prior art constructions closely restricted the movement for relatively free rotation about a dynamic axis when under a slightly unbalanced load and these were provided with means to connect with the rigid bolster beyond the limited angle of free inclination. These resulted in a greater degree of unbalance than with the conventional spindle used in ordinary operations.

Other constructions are so elaborate as to be impractical for commercial application.

An object of the invention is to provide a two-member, universally-connected spindle bearing construction floated in a flexible suspension and positively driven at high speeds, the spindle member which carries the yarn package being tiltable in a plane perpendicular to the axis of rotation and being driven by an eccentrically pinned or other positive connection to cause all parts to ratate at the same number of revolutions per minute.

Other and further objects of the present invention will appear from the more detailed description set forth below, it being understood that such detailed description is given by way of illustration and explanation only and not by way of limitation, since various changes therein may be made by those skilled in the art without departing from the scope and spirit of the present invention. In connection with that more detailed description, there is shown in the drawings, in

Figure 1 a view in vertical elevation of an embodiment of the invention;

Figure 2 a view in vertical elevation and in section of an embodiment of the invention;

Figure 3 a view in vertical elevation and in section of an embodiment of the invention.

In Figures 1 and 2, the base 1 is rigidly attached to Spindle bearings, large enough to provide some inertia against quick movements. The base is itself floated in a flexible suspension 14 to reduce the transmission of any appreciable vibration out, and to prevent vibration resistance from disturbing the center of gravity during op eration.

Bearings 2, and their hearing combinations the designed to withstand light but constant thrust loads, and varying radial loads. The bearings forms illustrated are single row ball in Figure 2; double row ball in Figure 1, where the whirl is not centered over the bearing, and an externally self-aligning ball bearing having a spherical housing for the outer race, Figure 3;

Means 3 is provided for assuring positive drive of the spindle by the whirl sleeve 6. This positive drive is in the form of pin in drilled recesses for Figure 1 (with a loose fit recess so that spindle can be tilted readily), and is in the form of a corrugation spring steel insert in Figure 2. In Figure 3 the means is a direct press fit of the spindle into the whirl sleeve 6.

Element 4 indicates the spindle base terminal, which in each of the sketches is spherically shaped for ease in tilting itself during operation to slightly inclined angles, as will be described later. The spindle terminal in Figure 3 is utilized as a whirl sleeve. A rubber or other elastic connection can be substituted for this spherical shape, and will allow tilting; however, tests show that an elastic connection to the bearing allows the spindle terminal to rotate more off the geometric center of each revolution, which is not desirable in this form of spindle.

The cross-mark 5 designates the theoretical center of the terminal sphere, about which centerany tilting or inclination of the spindle takes place. This center also is held as nearly stationary as possible, and the torque forces are applied in a constant plane about the center. This theoretical center of the terminal sphere should also be very near the center of gravity of the individual floated base.

Each of the numerals 6 represents the pulley or whirl and attached sleeve, which receives power from a driving tape or belt, rotates about the axis of the driven bearing race, and produces torque forces on a constant plane about such vertical axis for transmission through the spherically-shaped spindle terminal to all of the spindle, attached package, etc.

Each of the numerals 7 represent means for holding the spindle approximately erect when it is not rotating, but not with suflicient resistance to produce any appreciable strain under slight tilts during operation. In Figure 1 this is in the form of an elastic material constantly in contact with both the spindle and the drive sleeve. In Figure 2 this is nothing more than a raised surface on the spindle shaft, which when the spindle is at rest, is in contact with one side only of the drive sleeve against which it rests, but which, when the spindle is rotating under balanced conditions does not make contact at all with the drive sleeve, since the latter has an interior surface of larger diameter. In Figure 3 the larger surface of the spherical bearing connected to the whirl sleeve under tension produces enough friction so that when the spindle has been moved to a new position, it tends to hold the new position. The purpose of all these parts designated by reference numeral 7 is to hold the spindle approximately in spinning position when idle, but not to resist greatly the movement of the spindle to its own dynamic center of gravity when operated at high speed.

There is provided a bobbin base or clutch 8 which prevents the bobbin under any condition from sliding down "against the drive sleeve. It also may be used to assist in a positive drive between the spindle and the bobbin.

The dynamic center of gravity of the spindle, is represented by 9, which, due to variations in density of bobbin aver n14 material, small inaccuracies in machine work, uneven wind or expansion of yarn on the package, etc., may not coincide exactly with the geometric center of the spindle shape. Any bobbin which is unbalanced for any reason will change the center of gravity of the rotating spindle of which it becomes an integral dynamic part, so that theoretical point 9 shifts within the spindle during variation in loads. This theoretical point is kept well away from the base terminal by having a long spindle shape.

The bobbin, spool or tube is 10 which is the yarn carrier. This is preferably driven from near the center of gyration of the spindle.

The yarn or other elongated material is represented as ill, which in these illustrations is being uptwisted or thrown as it is withdrawn from the rotating package. The same dynamic principles of self-balance would apply to a spindle being used for a receiving type twist, or to a centrifugal spinner.

A single strand of yarn 12 in the form of a balloon, is drawn over the end of the spindle to a take-up package of conventional design, not here illustrated. The feed of the yarn through a conventional pigtail or other stationary guide provides a centralizing force for assisting in keeping the individual base level within its flexible suspension. Similarly, the use of a conventional ringtraveler combination for the receiving-type of spindle provides a centralizing and leveling force for the flexible base. The centralizing forces from stationary yarn guides or traveler rings reduce strain on the yarn.

Means 13 are'provided for attaching the bearing to the stationary base in a secure manner.

Means 14 are provided for a flexible suspension of the individual base in a frame 16 to avoid the transmission of any strong vibration forces to or from the base. This connection is made of a resilient material such as rubber for dampening or floating the individual base.

The operations through which the mechanical parts go when the machine is turned on with the yarn strand connected to a take-up device is as follows:

The drive belt or'tape (not illustrated) runs around or against the pulley or whirl 6 to rotate it in a constant plane about a vertical axis. The pulley is securely connected to a race of the bearingZ which has minimum play tolerance, and which is rigidly connected with the base 1 so that the spinning axis is maintained on as nearly a constant and true plane as is possible, with a minimum of movement (due to the inertia of the base and the stabilizing effect of friction.) The torque of the pulley sleeve is constantly transmitted to the edges of the spindle terminal, which is in spherical form so that only those edges in the plane of rotation can be driven by the sleeve, even though the spindle 4 may be tilted at times to an angle not truly centered about the axis of rotation. In this manner the spindle readily leaves the support 7 against uneven gravity, tilts about the center 5, and rotates as nearly as possible about its dynamic center of gravity 9. The spinning axis passes through the two held points 9 and 5, and strongly resists any movement from this axis,

unless the center of dynamic Weight changes in which event the spinning axis readily shifts to the new center by a slight inclination of the spindle.

it will be seen that since the center is held comparatively stationary by the base 1, and since the torque and friction forces constantly direct the spindle to a true axis of rotation, the spindle is held dynamically erect without support from the point 7 being necessary during the operation. The spindle rotates about its true center of gravity, which may agree with or vary slightly from its geometrical shape of symmetry, depending on a number of factors. A strong centripetal force is developed at the center of gravity during rotation at high speeds. Centrifugal forces are automatically balanced against each other, including the centrifugal pull of the yarn itself in balloon.

If an unbalanced condition is introduced during operation, the spindle automatically inclines itself geometrically to even up the dynamic forces. This is true no matter at what point along the spindle the unbalanced force is applied, to the extent that the force can be felt by the spindle at its dynamic center of gravity. Obviously, however, a small part of the radial load must be borne by the bearing 2; this is, that part which can not be shifted by inclination of the spindle to be carried to the center of gravity of the spindle.

The universal joint drive is so constructed and arranged to prevent any interference with the position or plane of contact of the drive tape or belt and this results in security of alignment. The flexibly suspended base dampens the forces which develop between the individual base and the machine frame, and limits the centers of gyration quite effectively to the axis of the rigidly connected spindle parts. Within the rigid system at high speed, a state of dynamic balance is attained on the free axis which passes through the center of gravity of the spindle and connected parts and this balance strongly resists movement from the dynamic axis of rotation due to the gyroscopic force which becomes stronger and which stabilizes the spindle as speeds are increased. The geometric motion of inclination to the dynamic axis is not repeated with each revolution in the present construction as compared with the prior art. One self-adjustment beyond the critical speed range is instantly madeto eliminate substantially all of the unbalanced forces at their source, and this results in avoiding the above mentioned defects. Once the geometric movement to the dynamic axis has been made, the subsequent movement is substantially pure rotational movement.

The two-'membered universal joint connected spindle bearing construction of the present invention is effectively floated, mechanically, in the flexible base suspension, and

the initial alignment of the racing'spindle assembly provides for substantially automatically compensated balancing and alignment of the spindle and yarn package, pracvidualbase, little leverage is exerted to shorten the axis of the dynamic system and the damping from air friction is readily adjusted to compensate for such inclinations from the resultant dynamic axis. This positioning of the universal connecting means is facilitated by using an upward opening connecting bearing (see Figs. 1 and 2) or a downward opening bearing (Fig. 3).

A minimum of lateral movement is provided so as to maintain an automatically balanced condition instead of the adjustment necessary during each revolution as in the prior art devices. The racing spindle assembly compen sates for any offset imbalance. At the same time the device is kept light and stable. The difficulty of perfect balancing of the bobbin or yarn carrier, a principal obstacle at top speeds in the prior art, is substantially eliminated. Vibration which continues in unchecked fashion when there is encountered an unbalanced state of the revolving spindle in the prior art devices is substantially eliminated, and larger packages are capable of being used with the spindle of the present invention.

It is necessary in the present construction that the individual base be resiliently floated so that the center of mass of the rigidly connected parts can not be shifted from the spindle, but remain near the center of the spindle, well removed from the base. Otherwise, if enough reaction can be felt from the small precessionary and nutatory gyration always present in an objectrotating on a free axis, the stabilizing gyroscopic force may be overcome and the spindle would throw itself outward in gyrations of rapidly mounting moments of inertia, centered near the base attachment to the machine frame. This is so because the transverse moment of inertia of the ordinary spindle taken at any point along the geometric axis is higher than the axial moment of inertia; however, as stated above, the resiliently floated base will not give enough reaction to effect any substantial shift in the center of gyration, and this tendency toward instability is overcome. It is also helpful if the transverse moment of inertia of the spindle assembly is made considerably higher than the axial moment of inertia, by a long spindle design, since the angle of inclination in moving to a free axis under a given condition of unbalance would then be smaller, and since the center of mass of the spindle would then be further removed from the end of which attached at the base, lessening any danger that the center of gyration may be shifted to the base.

Because of the constant tendency of the small precessionary gyrations always present to find any positioning of the movable rigid parts which will produce an axis of rotation with a higher moment of inertia than the desired geometric axis, it is necessary to have the spindles universal connection with the floated base at a point along the axis where any radial load passes through or near the center of gravity of the individual base. Otherwise, the base, though it cannot be rotated, will tend to be brought into a counter-balanced gyrating pattern. It will be seen that if the universal connection is well removed from the center of gravity of the individual base, the tendency of the dynamic system to shorten its axis as much as possible will be given more leverage, and the parts may fly out of position and even bend or tear themselves apart under the effect of the tremendous kinetic energy present in rotation at high speeds. But with the spindle proper having its universal-type of connection at or near the center of gravity of the individual base, very little leverage is given the tendency to shorten the axis to a geometric position with a higher moment of inertia, and the friction from the air and from dampening of any movement of the individual base eliminate such danger and leave gyroscopic force as the strongest force controlling the free axis.

It is thought that the invention and its advantages will be understood from the foregoing description and it is apparent that various changes may be made in the form, construtcion and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing its material advantages, the forms hereinbefore described and illustrated in the drawings being merely preferred embodiments thereof.

What is claimed is:

1. A self-balancing spindle construction comprising a flexibly suspended base, a t-iltable vertical spindle having an upper body portion and a rounded lower terminal portion, means between said terminal rounded portion and said upper body portion to hold said spindle in a substantially erect position when it is not rotated, a spindle bearing rigidly secured to said base, a whirl sleeve secured to said bearing to engage a driving tape which drives said spindle, said whirl sleeve substantially enclosing said terminal rounded portion, said terminal rounded portion mounted in said whirl sleeve for universal movement with respect thereto at such a level that any radial load from the rotating spindle wilt pass substantially through the center of said terminal rounded portion and the center of gravity of said base, and air friction providing substantially the entire damping force on the rotation of the spindle.

2. A seif-balancing spindle construction as in claim 1,

wherein said body portion of said spindle is provided at its base with a bobbin clutch adapted to secure the inner bottom hollow of a bobbin base.

3. A self-balancing spindle construction as claimed in claim 1 in which said terminal rounded portion is provided with an eccentrically placed recess at the base thereof, and said whirl sleeve is provided with a central recess therein having a pin eccentrically mounted in said recess to provide an eccentric driving connection within said whirl sleeve for said spindle. 4. A self-balancing spindle construction comprising a flexibly suspended base, a spindle bearing rigidly attached to said base, a whirl sleeve rigidly attached to said bearing and having an extension with a central recess therein extending upwardly beyond the whirl sleeve, said whirl sleeve being shaped to engage a driving tape to drive said spindle, a freely lti lt'able vertical spindle having an upward body portion and a lower terminal spherically rounded portion, a resilient cusped shell held within said recess in said sleeve and enclosing said terminal rounded portion to grip it as a universal connecting means and under suflicient tension to provide a positive driving engagement with said whirl sleeve, said universal connecting means connected to said terminal rounded portion at such a level that any radial load from the rotating spindle will pass substantially through the center of said terminal rounded portion and the center of gnavity of said base, and air friction providing substantially the entire damping force on the rotation of the spindle.

5. A self-balancing spindle construction comprising a flexible suspended base, an externally self-aligning bearing rigidly attached at the center of said base, a freely tiltable vertical spindle comprising an upper body portion and a lower rounded terminal portion, the external surface of said spindle bearing having a spherically rounded surface forming said terminal portion, a whirl sleeve attached around said hearing by an internally spherically rounded universal connecting portion frictiona lly gripping the terminal rounded portion, and the external surface on said whirl sleeve being shaped to engage a driving tape to drive said spindle, said terminal rounded portion mounted in said whirl sleeve at such a level that any radial load from the rotating spindle will pass substantially through the center of said terminal rounded portion and the center of gravity of said base, and air friction providing substantially the entire damping force on the rotation of the spindle.

References Cited in the file of this patent UNITED STATES PATENTS 425,930 Burlingame Apr. 15, 1890 570,997 Hughes Nov. 10, 1896 2,304,370 Neal Dec. 8, 1942 2,479,168 Keene et a1. Aug. 16, 1949 2,525,911 Keene et al. Oct. 17, 1950 2,611,231 Keene Sept. 23, 1952 

